IM6016
REDI-MIG
®
Plus 215C, 255C, 255S
Page 23
Section 8 - GROUND TEST PROCEDURE
The following procedures refer to the REDI-MIG
®
210c & 250c
Procedure for Replacing PC Boards
Before replacing a PC board suspected of being defective,
visually inspect the PC board in question for any visible damage
to any of its components and conductors on the back of the board.
1.
If there is no visible damage to the PC board, install a new
one and see if this remedies the problem. If the problem
is remedied, reinstall the original PC board to see if the
problem still exists. If the problem no longer exists with the
old PC board:
a. Check the PC board harness connector pins for
corrosion, contamination, or looseness.
b. Check leads in the machine harness for loose or
intermittent connection.
2.
If PC board is visibly damaged, before possibly subjecting
the new PC board to the same cause of failure, check for
possible shorts, opens or grounds caused by:
a. Damaged lead insulation.
b. Poor lead termination, such as a poor contact or a short
to adjacent connection or surface.
c. Shorted or open motor leads, or other external leads.
d. Foreign matter or interference behind the PC board.
3.
If PC board is visibly damaged, inspect for cause, then
remedy before installing a replacement PC board.
Note:
This procedure is for ‘machines as built’ many modifications
could have taken place over the life of a particular machine, so
details of this procedure may need to be ‘adjusted’ to suit these
modifications.
For prompt service contact your local authorised Lincoln Electric
Field Service Shop.
The insulation resistance values listed below are from Australian
Standard AS60974.1.
1)
Disconnect input cable from power supply.
2)
Disconnect gun assembly and work cable.
3)
Remove the side panel from power source.
4)
Jumper the two (2) AC terminals and both output terminals
of the bridge rectifier, (a total of three (4) places).
5)
Disconnect the PCB plug.
6)
Switch the control rotary switch to position ‘one’ (1) and
switch the on/off switch to on.
7)
Primary Test:
Connect one lead of the mega tester to
the frame of the machine and the other lead to the Active
terminal of the input plug. Apply the test. (Min. resistance
2.5MΩ)
8)
Welding circuit test:
Connect one lead of the mega tester
to the frame of the machine and the other lead to the (+)ve
output stud. Apply the test. (Min. resistance 2.5MΩ)
9)
Welding circuit to primary test:
Connect one lead of the
mega tester to the (+)ve output stud and the other lead to
the Active terminal of the input plug. Apply the test. (Min.
resistance 5MΩ)
10)
Transformer thermostat test:
Connect one lead of the
mega to the frame of the machine and the other lead to
the rectifier thermostat terminals. Apply the test. (Min.
resistance 2.5MΩ)
11) Remove all jumpers and reconnect all leads and plugs.
12) Refit all panel work previously removed.
WARNING
ELECTRIC SHOCK
can kill
This procedure is only suitable for applications using DC
mega testers up to 500V.
